Spatial-temporal characteristics of agricultural carbon emissions and influencing factors in the Hexi Corridor from 2000 to 2020

Abstract

农业是一个较为复杂的温室气体源/汇系统，不同区域、不同种养情况导致农业系统呈现碳源或碳汇两种情况。分析农业系统中碳排放特征及其影响因素，对实现农业绿色发展具有重要的意义，也为推动实现“碳达峰”“碳中和”目标提供数据依据。本研究以河西走廊为例，测算了2000—2020年河西走廊地区20个县市的农业碳排放量，并分析了农业碳排放时空特征及其影响因素。结果显示：2000—2020年河西走廊地区农业碳排放呈现缓慢上升状态。农业碳排放量最大的区域为凉州区和甘州区，占河西走廊地区农业碳排放总量的31.74%。从种植业与养殖业来看，河西走廊地区种植业为碳汇，碳吸收量达1.41×10⁸ t，养殖业为碳源，碳排放量达4.17×10⁷ t。2000—2020年河西走廊地区农业净碳排放量呈现起伏变化，但总体呈下降趋势，农业系统向碳汇转变。在种植业中对农业碳排放影响最大的因子为种植规模，在规模稳定发展区域影响最大的因素为机械化程度，在规模较小的区域主要影响因素为农村用电量；在养殖业中对规模较大区域和养殖业占比较高区域影响最大的因素为养殖规模，关联度在0.90以上。2000—2020年河西走廊地区农业碳排放强度表现为从随机分布到显著聚集的过程，农业碳排放重心缓慢向东南方向转移，但仅在张掖市内迁移。

Agriculture comprises a complex greenhouse gas source and sink system. Different regions and planting and breeding conditions lead to two types of carbon sources or sinks in the agricultural systems. Identifying the characteristics of carbon emissions in agricultural systems and influencing factors is of great significance to achieve green agricultural development, which will also provide a data basis to promote the realization of “carbon peak” and “carbon neutrality” goals. Taking the Hexi Corridor as an example, we calculated and analyzed the spatial and temporal characteristics of agricultural carbon emissions and influencing factors in 20 counties in the Hexi region from 2000 to 2020. The following results were obtained：from 2000 to 2020, agricultural carbon emissions in Hexi showed a slow increase. The regions with the largest agricultural carbon emissions were Liangzhou District and Ganzhou District, accounting for 31.74% of the total agricultural carbon emissions in Hexi. From the perspective of planting and stockbreeding, the planting industry in the Hexi region was determined to be a carbon sink, with carbon absorption of 1.41×10⁸ t, and stockbreeding was considered a carbon source, with carbon emissions reaching 4.17×10⁷ t. From 2000 to 2020, the net carbon emissions of agriculture in Hexi showed fluctuations, but the overall trend was decreasing, and the agricultural system changed to carbon sinks. In the planting industry, the factor with the greatest impact on agricultural carbon emission was determined to be planting scale, and in regions with stable scale development, the factor with the greatest impact was found to be the mechanization degree. The main influencing factors for smaller regions were the rural electricity consumption. In the agricultural area with a large scale and high proportion of stockbreeding industry, the most influential factor was the stockbreeding scale, and the correlation degree was greater than 0.9. From 2000 to 2020, the agricultural carbon emission intensity in the Hexi region showed a process of random distribution to significant aggregation, and the center of agricultural carbon emission shifted slowly to the southeast, but only in Zhangye City.